The present invention relates to electric power systems, and more particularly, but not exclusively, relates to management of electric power provided by a system including a variable speed generator driven by an engine and an electric energy storage device.
In many applications of electrical generator systems, load demand is typically low relative to generator power capacity. In contrast, generator selection is often driven by peak power requirements, resulting in an “oversized” generator most of the time. As an alternative, in certain situations power generation systems could include an electrical energy storage device to supplement generator power during peak usage, which facilitates a reduction in generator size. The generator can be selected with sufficient capacity to charge the storage device at the same time it supplies power to electrical loads below a given level.
In certain applications, a power system is installed in a vehicle that includes a dedicated engine/generator set and electrical energy storage device in the form of one or more electrochemical batteries. The noise resulting from generator operation can be of concern under certain circumstances making it desirable to provide a “silent” operating mode, during which time power is sourced only from the batteries and the engine/generator set is inactive. In most current applications, the engine/generator set subsystems and the electrical energy storage device subsystems come from independent sources and tend to work independent of one another. Unfortunately, the ability to desirably integrate and collectively manage generator and electrical storage device operation can be challenging. Alternatively or additionally, it can prove challenging to reduce size/weight of the power system and/or attendant noise/vibration caused by engine/generator set operation. Thus, there is an ongoing demand for further contributions in this area of technology.